In modern processor package architecture, contact pitches are shrinking to accommodate narrower and more crowded trace routing to direct increasingly faster signals within and between devices. For example, incorporation of high-bandwidth external memory with microprocessors and logic integrated circuits (ICs) in a single package requires a high-density of interconnection capability between the memory and microprocessor ICs. Conventional IC package substrate architectures typically have wide interconnect and routing pitch, and therefore do not support high-density interconnections that utilize sub-100-micron interconnect pitches. Conventional IC package substrate architectures may also require the use of bridging dies to provide an interface between low-density package substrate interconnects to high density IC interconnect architectures.